package storm.trident.operation.impl;

import java.util.Map;

import storm.trident.operation.Filter;
import storm.trident.operation.Function;
import storm.trident.operation.TridentCollector;
import storm.trident.operation.TridentOperationContext;
import storm.trident.tuple.TridentTuple;


// works by emitting null to the collector. since the planner knows this is an ADD node with
// no new output fields, it just passes the tuple forward
public class FilterExecutor implements Function {
    Filter _filter;


    public FilterExecutor(Filter filter) {
        _filter = filter;
    }


    @Override
    public void execute(TridentTuple tuple, TridentCollector collector) {
        if (_filter.isKeep(tuple)) {
            collector.emit(null);
        }
    }


    @Override
    public void prepare(Map conf, TridentOperationContext context) {
        _filter.prepare(conf, context);
    }


    @Override
    public void cleanup() {
        _filter.cleanup();
    }

}
